(1) Field of the Invention
The present invention relates to a substrate processing apparatus and a substrate processing method.
(2) Description of Related Art
Substrate processing apparatuses are used to subject various substrates such as semiconductor substrates, and substrates for liquid crystal displays, plasma displays, optical disks, magnetic disks, magneto-optical disks, and photomasks to various types of processing (see JP 2009-32898 A, for example).
The substrate processing apparatus discussed in JP 2009-32898 A includes a coating processing unit that forms a resist film on a substrate, a development processing unit that performs development processing for a resist film on the substrate, a transport robot that transports the substrate, and an edge exposure unit that performs exposure processing for a peripheral edge of the resist film on the substrate. In the edge exposure unit, exposure processing is performed when the substrate held in a holding and rotating unit is rotated while a peripheral edge of the substrate is irradiated with light. Edge data representing an edge of the substrate held in the holding and rotating unit is acquired. Based on the edge data, an amount of eccentricity of the center of the substrate from a rotation center of the holding and rotating unit is calculated. Thus, the presence or absence of an abnormality in the amount of eccentricity of the substrate in the edge exposure unit can be determined.
In the coating processing unit, a resist liquid is supplied onto the substrate rotated by a spin chuck. At this time, a rinse liquid is supplied to the peripheral edge of the substrate so that a resist liquid on the peripheral edge of the substrate is removed. Thus, a resist film is formed in a region excluding the peripheral edge of the substrate. Since the resist film is not formed on the peripheral edge of the substrate, a holder in a transport robot can hold the peripheral edge, where no resist film exists, of the substrate.
If the rotation center of the spin chuck in the coating processing unit is eccentric from the rotation center of the substrate, however, the width of the peripheral edge, where no resist film exists, of the substrate varies. If a supply state of the rinse liquid is not appropriate, the width of the peripheral edge, where no resist film exists, of the substrate cannot be made appropriate. Thus, the holder in the transport robot may contact a part of the resist film on the substrate. As a result, the resist film on the substrate may be damaged, and particles of the resist film may be generated.
The edge exposure unit discussed in JP 2009-32898 A can neither detect an abnormality in the amount of eccentricity of the substrate in the coating processing unit nor detect a supply state of the rinse liquid in the coating processing unit.